Coal tar shampoo was a standby for psoriasis and eczema. So why HAS this trusted skin treatment disappeared?

For decades, Ray Jobling has used a special medicated shampoo to help control his psoriasis. The condition is caused by overproduction of skin cells, leading to a build-up of itchy and sore patches of skin.

Psoriasis can appear anywhere on the body, but is most common on the scalp, elbows, knees and lower back.

Ray, a 72-year-old retired Cambridge University academic, has psoriasis on his scalp and has long relied on Polytar, a shampoo made with coal tar, a by-product of the industrial process that turns coal into coke.

Coal-tar shampoo, an over-the-counter product, has been a standby for psoriasis and other skin conditions, including eczema and cradle cap, for years.

But 18 months ago, it suddenly started disappearing from chemists' shelves for reasons that are far from clear.

Ray's doctor suggested he try Carbo Dome, a coal tar cream - but then a year ago this, too, started to vanish.

Ray, who was diagnosed with psoriasis when he was 14, says for those with painful skin conditions, losing a product that has been relied on for years can have a big impact (2 per cent of the population has psoriasis).

'Polytar had been my mainstay treatment for as far back as I can remember. Then it just disappeared. There were huge numbers of people using this product and it is a very serious matter,' says Ray, chairman of the Psoriasis Association.

'Psoriasis can make the skin crack. I have ended up in hospital as it can affect your body's ability to control temperature.'

Coal tar, a thick brown substance, reduces itchiness and inflammation. It's not clear exactly how it works, but one theory is it reduces the production of DNA and therefore new cells. Coal tar in skin creams, bath oils and shampoos is also used to treat eczema, reducing inflammation and itchiness.

The shortage is driving people to paying hugely inflated sums on the internet to buy it from abroad, mainly from Thailand. On Amazon, a 250ml bottle of Polytar can cost more than £21 - in the UK it used to cost just over £2. Both the Psoriasis Association and the National Eczema Society have been contacted by many people affected by the problem.

'It is a hot topic on our discussion forums,' says Carla Renton, information and communications manager at the Psoriasis Association. 'It is traumatic if treatment you have used for a long time is suddenly removed, especially when we don't know why.

Coal-tar shampoo, an over-the-counter product, has been a standby for psoriasis and other skin conditions

'Psoriasis is a lifelong condition, and it can have a big impact on quality of life due to discomfort and poor confidence, so if you find something that works it is really important.'

So why are coal tar shampoo and bath treatments disappearing?

In the past, coal tar has had a reputation as being messy and unpleasant to use. There have also been concerns about its safety. In 1985, a study of people who had worked with coal tar for 40 years found that almost half developed skin cancer. In 2000, the European Commission's Scientific Committee on Cosmetic Products and Non-Food Products Intended for Consumers said using coal tar in shampoo had an 'unacceptable high risk of skin cancer'.

Yet an article in the Journal of the American Academy of Dermatology in 2009 suggested there was no cancer danger using coal tar to treat skin. And in 1991, the U.S. Food and Drug Administration said the amount used in over-the-counter products is safe.

The Medicines and Healthcare products Regulatory Agency (MHRA), which licenses medical products here, has also said there were no safety concerns around the use of coal tar in regulated medication.

'Polytar had been my mainstay treatment for as far back as I can remember. Then it just disappeared'

The EU brought in a new tougher rule banning it in cosmetics last year over fears it might be carcinogenic. Even though Polytar and Carbo Dome are not cosmetics, could this be the problem?

Ray certainly believes so. 'It has changed the climate around coal tar within the European market and I think it may have had an effect.' Carla Renton says she has struggled to get a clear answer from pharmaceutical companies on what is causing the shortages.

Indeed, when the Mail spoke to the manufacturers, they gave a variety of explanations.

Sandoz, which makes Carbo Dome, said its supplier had stopped producing coal tar, so the product would be unavailable until another supplier was found, and stressed there were no safety concerns.It also claimed it was working with the MHRA on the product's licence, although a spokesperson for the agency said they had no issues with its licensing.

GlaxoSmithKline says changes to licensing and producing Polytar meant supply would not be restored until 2016.

'Communication has been poor, so often the first we will hear about it is a patient saying they can't get a product we have prescribed.'

She suggests another factor may be that coal tar products are less profitable than newer remedies - a skin cream called Dovobet, which contains steroids and vitamin D, costs the NHS £61.55 for 120g, compared to £16.38 for 100g of Carbo Dome. However, the manufacturers deny the price is a factor in the shortages.

In the meantime, Ray Jobling fears people may end up using stronger medication, such as topical steroid creams that have more side-effects, such as thinning the skin. 'Treatment options for psoriasis are not that good. When a treatment disappears, it really matters,' he says.